Quarantine treatment for wheat seeds infested by Tilletia controversa
Experiments were carried out in Oregon (US) to evaluate the effects of a high temperature sodium hypochlorite treatment on germination of wheat seeds and its associated Tilletia controversa (EPPO A2 quarantine pest) teliospores in order to develop a quarantine procedure for wheat consignments infested by the pest. Contaminated winter wheat seed lots were exposed for 15, 30 or 60 s to 0,07, 0,13, 0,27 or 0,67 M NaOCl solutions which were heated up to 50ø, 55ø or 60ø C. It was determined that the maximum T. controversa teliospore mortality was achieved when the NaOCl concentration was ó0,13 M. Seed germination varied in different winter wheat cvs. in dependence to temperature, exposure time and NaOCl concentration. The safest NaOCl concentration for killing teliospores of T. controversa and successful germination was 0,13 M when treatment temperature was ó 55øC. The authors suggest that the high temperature NaCl treatment might be an important tool for solving phytosanitary restrictions imposed due to the presence of T. controversa teliospores on wheat grains and seeds.
Sources
Chastain, T.G. (1991) High-temperature sodium hypochlorite effects on viability of of Tilletia controversa teliospores and wheat seeds.
Crop Science 31, 1327-1330